He could that something was wrong, that you were upset about something and didn't really want to talk about it either.
He was supposed to be a hero, your hero. How was he supposed to help you in you didn't let him in?
At first he noticed these quick glances into the mirror before quickly looking away in contempt. He noticed the way you would silently compare yourself to others you passed by on the street.
For all of Michael's faults and frequent failure of reading the room, he always made sure to keep an eye out for signs when you were feeling dysphoric about yourself.
So as you stand infront of the mirror pick at everything you deem "wrong" with your body and appearance he slowly creeps up behind you in hopes to distract you with something more positive or uplifting.
"So, I was thinking," He starts as he peeks his head over your shoulder. "Why don't we watch a movie? Or we can bake something!" He smiles confidently despite the baking incident from the last time you two baked together. But his goal is to cheer you up. "Let's do something fun and you can tell me about how you've been feeling lately."